The present invention relates to a data processing network of the type in which a plurality of client computer systems are connected to a server computer system.
In a typical network environment, multiple client computer systems (clients) are connected to one or more server computer systems (servers). In a first common arrangement, each client system includes an operating system and optionally other software, stored on a hard file within the client. On power-up or reboot the client boots from the operating system stored on the hard file without reference to the server computer. This type of boot is called a local program load. Other application software e.g. word processing, database software etc, held on storage associated with the server system, is accessed as needed by the client system.
In an alternative network configuration, the client computer does not boot from a locally stored operating system. One reason for this is that the client system does not have a local mass storage device such as a hard file on which the operating system software can be stored. Consequently, when such a client system is powered-up, the client fetches its operating system software from the server system and stores the software in volatile storage for use until the client system is powered-off. This process is called Remote Initial Program Load (hereinafter termed xe2x80x98RPLxe2x80x99).
A network of the second type in which each client system RPLs from a server system (an RPL network) has an advantage over the first type of network configuration in that the network administrator has full control over the software being used by the client. Thus the network administrator is able to control the operation and configuration of all the client systems with one consequence that the client users can be prevented from installing and using undesirable and/or unlicensed software on their client systems. By controlling the network from the server in this manner, the overall network maintenance costs are lower thus leading to lower overall operating costs.
However, an RPL network has a number of disadvantages, not the least of which is high network loading caused when a large number of clients RPL at one time. This overloading can cause disruption and reduced efficiency especially in large network environments. One way in which the effects of network overloading can be reduced is by providing a higher ratio of server to client systems. Typically this ratio will be 1:10 in an RPL network, whereas in the first type (xe2x80x9cnon-RPLxe2x80x9d) of network a typical ratio is more of the order of 1:100. As server systems are generally more expensive than client systems, this increase in ratio will raise the overall equipment costs of the network thus largely negating the lower maintenance costs.
It would be a desirable objective to provide for a network and a method of network operation which combines some or all of the advantages of both network configurations while avoiding most or all of the aforementioned disadvantages.
Accordingly, in a first aspect of the present invention, there is provided a method of booting a client data processing system attached to a control data processing system in a data processing network comprising: at power-on or re-boot of a client system, issuing an initial program load request from the client system onto the network; and responsive to the receipt of the initial program load request at the control system, transferring bootstrap code to the client to cause the client to boot from operating system code stored on a mass storage device of said client.
By this method, the client system is forced to issue an RPL request to the control system (server) which then controls the boot of the client system thereby preventing the client user from carrying out an unauthorised local boot operation.
In a preferred method, the client system BIOS specifies that the client may boot only from the control system, thereby forcing the client to issue the initial program load request onto the network. In a preferred method, this boot setting of the BIOS is protected by a control-system defined password.
Viewed from a second aspect of the invention, there is provided a method of booting a client data processing system attached to a control data processing system in a network comprising: at power-on or reboot of said client system, issuing an initial program load request from a client system onto the network; and responsive to the receipt of the request at the control system, either transferring, according to a first mode of operation, bootstrap code to the client system to cause the client to boot from operating system stored on a mass storage device of the client; or transferring, according to a second mode of operation, bootstrap code to cause the client system to boot from the control system.
In a preferred method according to the second aspect, the two modes of operation are defined in the control system and are selectable by the network administrator. Thus in the first modexe2x80x94referred to in the detailed description as the normal modexe2x80x94the client system is able to boot from the local hard file but only as permitted by the network administrator. If the administrator wishes to take control over the software on the client system e.g. for software installation or client system maintenance, the administrator changes the boot set-up for the client to force a boot according to the second (special) mode of operation.
In a preferred method, the second mode of operation comprises the further step of downloading control-system-specified software to the client system. On completion of the downloading of the control-system specified software to the client, the boot set-up for that client in said control system may be changed so that on next re-boot or power-on, the client will boot from the control-system defined software according to the first mode of operation.
The control-system specified software may be an upgrade to the existing operating system software stored on the mass storage device, whereby the method comprises the further step of replacing the existing software on said mass storage device with said upgraded software.
A client system in the form of a personal computer system will include BIOS code stored in non-volatile storage (e.g. ROM) in said client. In one preferred method, the control-system specified software is an upgrade to the BIOS code, the method comprising the further steps of storing the upgraded BIOS in said non-volatile storage.
In a preferred method according to the invention, the second (special) mode of operation is employed to install software onto a client system which has been newly connected to the network. In such a client system which initially has no operating software stored on said mass storage device, the control-system-specified software comprises operating system software for installation on said device, the method comprising the step of installing the operating system software on said mass storage device.
In a client system wherein BIOS code is stored in non-volatile storage and wherein the BIOS settings (including the location of the boot device) are protected by a BIOS password, the method of the present invention is advantageously employed to allow for the updating, under the control of the network administrator, of the BIOS password.
According to a third aspect of the invention there is provided a data processing network comprising a control data processing system connected to a plurality of client data processing systems, the control system including means responsive to an initial program load request received from a client system to transfer a bootstrap program to the requesting client to cause the client to boot from operating system software stored on a mass storage device of said client system.
A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings.